In 1979 he received two Primetime Emmy Award nominations in the category Outstanding Achievement in Makeup for his work on the television series Roots: The Next Generations, shared with Zoltan Elek, and in the category Outstanding Individual Achievement – Special Class for the television documentary General Electric's All-Star Anniversary.

Other credits as makeup artist include the crime thriller Johnny Firecloud (1975), the horror film Shivers (1975), the horror film Ilsa, Harem Keeper of the Oil Sheiks (1976, starring Dyanne Thorne), the game show Password Plus (1979), the television fantasy adventure The Archer: Fugitive from the Empire (1981, directed by Nicholas Corea and hair styling by Gerald Solomon), the television drama The Children Nobody Wanted (1981), the drama Honkytonk Man (1982), the television series Bosom Buddies (1982, makeup design by Michael Westmore) and Family Ties (1982-1984), the fantasy comedy Oh God! You Devil! (1984), the television mini series The Atlanta Child Murders (1985), the television series MacGyver (1985-1986) and Our House (1986, directed by Robert Scheerer), the fantasy comedy Wicked Stepmother (1989, with Dayne Johnson), the television series Dark Shadows (1991, starring Ben Cross, Jean Simmons, Julianna McCarthy, and Michael Cavanaugh), and the television comedy The Cherokee Kid (1996, with Brian McManus).

Other work as day check makeup artist or key assistant makeup artist includes the television series Knots Landing, Perfect Strangers, The Golden Girls, Murphy Brown, B.J. and the Bear, Matlock, Remington Steele, The Bold and the Beautiful, The Young and the Restless, Night Court, Sisters, Dynasty, The Fall Guy, Hardcastle & McCormick, The Love Boat, The Gong Show, Hollywood Squares, General Hospital, Jeopardy, Wheel of Fortune, Days of Our Lives, Married with Children, The A-Team, and Alien Nation.

Among his film work are the horror film Poltergeist (1982, with Craig Reardon and Toni-Ann Walker),the science fiction film Ice Pirates (1984), the comedy The Adventures of Buckaroo Banzai Across the 8th Dimension (1984, with Bari Dreiband-Burman and Steve LaPorte), the science fiction film The Last Starfighter (1984), the comedy Down and Out in Beverly Hills (1986, with Edouard F. Henriques), the science fiction sequel Terminator 2: Judgement Day (1991) on which he also performed stunts, the horror film Dracula (1992), the comedy sequel Hot Shots! Part Deux (1993), the comic adaptation The Shadow (1994), the thriller On Deadly Ground (1994), the crime drama Things to Do in Denver When You're Dead (1995), the sequels Batman Returns (1992) and Batman Forever (1995), and the science fiction blockbuster Independence Day (1996).

With over twenty-one years of teaching experience, Dittmar worked as teacher in California, Texas, and Osaka, Japan. Between 1996 and 1997 and 2000 and 2002 he taught at the Learning Tree University in Chatsworth, California.